+static void yaffs_flush_single_cache(struct yaffs_cache *cache, int discard)
+{
+
+ if (!cache || cache->locked)
+ return;
+
+ /* Write it out and free it up if need be.*/
+ if (cache->dirty) {
+ yaffs_wr_data_obj(cache->object,
+ cache->chunk_id,
+ cache->data,
+ cache->n_bytes,
+ 1);
+
+ cache->dirty = 0;
+ }
+
+ if (discard)
+ cache->object = NULL;
+}
+
+static void yaffs_flush_file_cache(struct yaffs_obj *obj, int discard)
+{
+ struct yaffs_dev *dev = obj->my_dev;
+ int i;
+ struct yaffs_cache *cache;
+ int n_caches = obj->my_dev->param.n_caches;
+
+ if (n_caches < 1)
+ return;
+
+
+ /* Find the chunks for this object and flush them. */
+ for (i = 0; i < n_caches; i++) {
+ cache = &dev->cache[i];
+ if (cache->object == obj)
+ yaffs_flush_single_cache(cache, discard);
+ }
+
+}
+
+
+void yaffs_flush_whole_cache(struct yaffs_dev *dev, int discard)
+{
+ struct yaffs_obj *obj;
+ int n_caches = dev->param.n_caches;
+ int i;
+
+ /* Find a dirty object in the cache and flush it...
+ * until there are no further dirty objects.
+ */
+ do {
+ obj = NULL;
+ for (i = 0; i < n_caches && !obj; i++) {
+ if (dev->cache[i].object && dev->cache[i].dirty)
+ obj = dev->cache[i].object;
+ }
+ if (obj)
+ yaffs_flush_file_cache(obj, discard);
+ } while (obj);
+
+}
+
+/* Grab us an unused cache chunk for use.
+ * First look for an empty one.
+ * Then look for the least recently used non-dirty one.
+ * Then look for the least recently used dirty one...., flush and look again.
+ */
+static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
+{
+ int i;
+
+ if (dev->param.n_caches > 0) {
+ for (i = 0; i < dev->param.n_caches; i++) {
+ if (!dev->cache[i].object)
+ return &dev->cache[i];
+ }
+ }
+
+ return NULL;
+}
+
+static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
+{
+ struct yaffs_cache *cache;
+ int usage;
+ int i;
+
+ if (dev->param.n_caches < 1)
+ return NULL;
+
+ /* First look for an unused cache */
+
+ cache = yaffs_grab_chunk_worker(dev);
+
+ if (cache)
+ return cache;
+
+ /*
+ * Thery were all in use.
+ * Find the LRU cache and flush it if it is dirty.
+ */
+
+ usage = -1;
+ cache = NULL;
+
+ for (i = 0; i < dev->param.n_caches; i++) {
+ if (dev->cache[i].object &&
+ !dev->cache[i].locked &&
+ (dev->cache[i].last_use < usage || !cache)) {
+ usage = dev->cache[i].last_use;
+ cache = &dev->cache[i];
+ }
+ }
+
+#if 1
+ yaffs_flush_single_cache(cache, 1);
+#else
+ yaffs_flush_file_cache(cache->object, 1);
+ cache = yaffs_grab_chunk_worker(dev);
+#endif
+
+ return cache;
+}
+
+/* Find a cached chunk */
+static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
+ int chunk_id)
+{
+ struct yaffs_dev *dev = obj->my_dev;
+ int i;
+
+ if (dev->param.n_caches < 1)
+ return NULL;
+
+ for (i = 0; i < dev->param.n_caches; i++) {
+ if (dev->cache[i].object == obj &&
+ dev->cache[i].chunk_id == chunk_id) {
+ dev->cache_hits++;
+
+ return &dev->cache[i];
+ }
+ }
+ return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
+ int is_write)
+{
+ int i;
+
+ if (dev->param.n_caches < 1)
+ return;
+
+ if (dev->cache_last_use < 0 ||
+ dev->cache_last_use > 100000000) {
+ /* Reset the cache usages */
+ for (i = 1; i < dev->param.n_caches; i++)
+ dev->cache[i].last_use = 0;
+
+ dev->cache_last_use = 0;
+ }
+ dev->cache_last_use++;
+ cache->last_use = dev->cache_last_use;
+
+ if (is_write)
+ cache->dirty = 1;
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
+{
+ struct yaffs_cache *cache;
+
+ if (object->my_dev->param.n_caches > 0) {
+ cache = yaffs_find_chunk_cache(object, chunk_id);
+
+ if (cache)
+ cache->object = NULL;
+ }
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
+{
+ int i;
+ struct yaffs_dev *dev = in->my_dev;
+
+ if (dev->param.n_caches > 0) {
+ /* Invalidate it. */
+ for (i = 0; i < dev->param.n_caches; i++) {
+ if (dev->cache[i].object == in)
+ dev->cache[i].object = NULL;
+ }
+ }
+}
+
+static void yaffs_unhash_obj(struct yaffs_obj *obj)
+{
+ int bucket;
+ struct yaffs_dev *dev = obj->my_dev;
+
+ /* If it is still linked into the bucket list, free from the list */
+ if (!list_empty(&obj->hash_link)) {
+ list_del_init(&obj->hash_link);
+ bucket = yaffs_hash_fn(obj->obj_id);
+ dev->obj_bucket[bucket].count--;
+ }
+}
+
+/* FreeObject frees up a Object and puts it back on the free list */
+static void yaffs_free_obj(struct yaffs_obj *obj)
+{
+ struct yaffs_dev *dev;
+
+ if (!obj) {
+ BUG();
+ return;
+ }
+ dev = obj->my_dev;
+ yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
+ obj, obj->my_inode);
+ if (obj->parent)
+ BUG();
+ if (!list_empty(&obj->siblings))
+ BUG();
+
+ if (obj->my_inode) {
+ /* We're still hooked up to a cached inode.
+ * Don't delete now, but mark for later deletion
+ */
+ obj->defered_free = 1;
+ return;
+ }
+
+ yaffs_unhash_obj(obj);
+
+ yaffs_free_raw_obj(dev, obj);
+ dev->n_obj--;
+ dev->checkpoint_blocks_required = 0; /* force recalculation */
+}
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj)
+{
+ if (obj->defered_free)
+ yaffs_free_obj(obj);
+}
+
+static int yaffs_generic_obj_del(struct yaffs_obj *in)
+{
+ /* Iinvalidate the file's data in the cache, without flushing. */
+ yaffs_invalidate_whole_cache(in);
+
+ if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
+ /* Move to unlinked directory so we have a deletion record */
+ yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
+ 0);
+ }
+
+ yaffs_remove_obj_from_dir(in);
+ yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
+ in->hdr_chunk = 0;
+
+ yaffs_free_obj(in);
+ return YAFFS_OK;
+
+}
+
+static void yaffs_soft_del_file(struct yaffs_obj *obj)
+{
+ if (!obj->deleted ||
+ obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
+ obj->soft_del)
+ return;
+
+ if (obj->n_data_chunks <= 0) {
+ /* Empty file with no duplicate object headers,
+ * just delete it immediately */
+ yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
+ obj->variant.file_variant.top = NULL;
+ yaffs_trace(YAFFS_TRACE_TRACING,
+ "yaffs: Deleting empty file %d",
+ obj->obj_id);
+ yaffs_generic_obj_del(obj);
+ } else {
+ yaffs_soft_del_worker(obj,
+ obj->variant.file_variant.top,
+ obj->variant.
+ file_variant.top_level, 0);
+ obj->soft_del = 1;
+ }
+}
+
+/* Pruning removes any part of the file structure tree that is beyond the
+ * bounds of the file (ie that does not point to chunks).
+ *
+ * A file should only get pruned when its size is reduced.
+ *
+ * Before pruning, the chunks must be pulled from the tree and the
+ * level 0 tnode entries must be zeroed out.
+ * Could also use this for file deletion, but that's probably better handled
+ * by a special case.
+ *
+ * This function is recursive. For levels > 0 the function is called again on
+ * any sub-tree. For level == 0 we just check if the sub-tree has data.
+ * If there is no data in a subtree then it is pruned.
+ */
+
+static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
+ struct yaffs_tnode *tn, u32 level,
+ int del0)
+{
+ int i;
+ int has_data;
+
+ if (!tn)
+ return tn;
+
+ has_data = 0;
+
+ if (level > 0) {
+ for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
+ if (tn->internal[i]) {
+ tn->internal[i] =
+ yaffs_prune_worker(dev,
+ tn->internal[i],
+ level - 1,
+ (i == 0) ? del0 : 1);
+ }
+
+ if (tn->internal[i])
+ has_data++;
+ }
+ } else {
+ int tnode_size_u32 = dev->tnode_size / sizeof(u32);
+ u32 *map = (u32 *) tn;
+
+ for (i = 0; !has_data && i < tnode_size_u32; i++) {
+ if (map[i])
+ has_data++;
+ }
+ }
+
+ if (has_data == 0 && del0) {
+ /* Free and return NULL */
+ yaffs_free_tnode(dev, tn);
+ tn = NULL;
+ }
+ return tn;
+}
+
+static int yaffs_prune_tree(struct yaffs_dev *dev,
+ struct yaffs_file_var *file_struct)
+{
+ int i;
+ int has_data;
+ int done = 0;
+ struct yaffs_tnode *tn;
+
+ if (file_struct->top_level < 1)
+ return YAFFS_OK;
+
+ file_struct->top =
+ yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
+
+ /* Now we have a tree with all the non-zero branches NULL but
+ * the height is the same as it was.
+ * Let's see if we can trim internal tnodes to shorten the tree.
+ * We can do this if only the 0th element in the tnode is in use
+ * (ie all the non-zero are NULL)
+ */
+
+ while (file_struct->top_level && !done) {
+ tn = file_struct->top;
+
+ has_data = 0;
+ for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
+ if (tn->internal[i])
+ has_data++;
+ }
+
+ if (!has_data) {
+ file_struct->top = tn->internal[0];
+ file_struct->top_level--;
+ yaffs_free_tnode(dev, tn);
+ } else {
+ done = 1;
+ }